Another alternator hits the dust and not under warranty

If you got overnight delivery you could have gift wrapped it for "her". A rose and a stator.

My girl's getting white turn signals for Valentines. If only the damn mailman would cooperate! To hell with $80/doz roses, I want something that will last longer than a week.

Interesting idea. Too bad she reads this thread.

sorry, I should have been more clear ... it was after 5PM when I posted that ...
I was thinking in terms of thermal conductivity ... not electrical ...

I know some epoxy resins are designed with thermal conductivity in mind, but for most formulations nobody cares.

I wish I had asked more questions about the potting compound Westinghouse used .... but that was a long time ago ...

Ha ha ha..... I am not sure of how that would apply here. In a CF matrix, the thermal coefficient of expansion, and thermal conductivity is very small. But as this stuff is lung around in ( flywheel, not stator) about 3-400 deg F. temps.... eventually it will pass through that temperature......

Back when you were interested in "pot", right?

There might be a hint of truth to that .....................

What a good idea. Flowers are a waste of money!

Re the F650 stator mentioned earlier in the thread, there are differences between the F650 and F650GS

The F650 is only 280 watts and the GS is 400 watts, some of the Co's offering stators get confused and lump them together

On the GS we have seen stators cook and epoxy break up and go through oil ways so I would not expect using one from the GS would be a good idea

It is almost up to 40F here today so I opened up my f650 to look at the stator.

Yep it is pretty toast..black. Pretty much like Emmmbeedee's wife's. Mine has not failed but I order a Electrosport today..mainly because they ship with connectors on.


when looking at the black stuff on the stator...I could not help but think of cabonized oil....not just the stator epoxy failing.

The carbonization is clearly worst on just some of the poles.

A wild an no way substantiated though that oil carbonizes on overly hot stator, build up the oil based carbon crud which act as insulation and accelerates the over heating process till hard failure occurs. could this mean that using more temperature resistant full syn oil would delay stator failure?

is this a case for only running full syn oil in the f800 engine?

I had heard that the early 650 singles were lower wattage(ie. carbureted versions). Both my 650CS and GS manuals for the later injected bikes rate the alt at 400W/14V. I'm no expert but I believe a lower W stator would have less windings or like on Honda XR R's, some poles aren't wound where the XR L's are fully. It was a trick to rewind the whole stator for more output on thr R's.

In any case, when the time comes I'll compare side by side. In an emergency, I'll take those lower watts over pushing.

Interesting assessment. After things have been cooked at 400 F., for a good long while, I would be hard pressed to, to id the diff. between a Polymer, and carbonized oil. It does seem plausible to me, that if oil caking builds up topside, it could add a heat insulator, preventing the coil from releasing enough heat to sustain itself.... Maybe.

I agree, looks like only the "bottom" coils have the caking
(if I'm looking at it correctly ... the wires come out the top/back of the side cover IIRC?)
Which would make those coils hotter making them cake more ... etc....

How high up in the side cover does the oil level come when the bike is running and on level ground...
Compared to the height of the stator ... I would think the oil level would not come up high enough to even partly submerge the stator ... but would have to hold the dip stick up to the side of the bike and "draw" the level lnie around the crankcase to be sure .... Anybody know off hand?

Before he shoved off to work for the competition Joel had made a "stator detunning" modification that he guessed would shave ~100W off the output of the stator ... which would still leave adequate output for use w/o heated clothing and would sure keep stator cooler ... but I don't think we'll ever find out how well that worked out

Maybe as a maint. item we need to clean the gunk off the stator every 12K miles or so? Sheezzzzzzzzzz

I don't own an F800 but had a Honda CBF1000, which are known to fry stators on a regular basis, mine fried at 22,000kms. I always run Amsoil full synthetic and that's what was in the bike from it's first service so I don't think synth is going to save the stator. My solution on the CBF was to install a CompuFire R/R along with the new stator and that setup ran to 38,000kms when I traded in the bike so not sure if that second stator is still running or not.

Yeah I bit the bullet and went Compufire on the new stator and redesigned flywheel! $1,000 later I better not see that stator burn up for at least another 60,000 miles.

With the bike running the oil level would be next to nothing. Remember also that the stator is surrounded by the rotor, which rotates? :huh So any oil would be flung centrifugally (today's word) all over the hot stator, which just screams as anyone would in that situation. The only time the oil level would possibly submerge it is when the bike is hot, upright and off. Further theorizing necessary on your part. I'm more of a criticizer.

Huh? That's just silly. Might as well unplug an injector to save gas while you're at it.

Oil does not get flung on the stator which is inside the rotor. It's simply not possible. It gets flung away from it.

I ordered a Rick's Stator this morning.

Where's the best/cheapest place to order the Compufire R/R?

I thought we all agreed that the stator was oil cooled? Oil is being flung onto it.

Anyways, you're missing the point. JrWoody was thinking there was a "high water mark" on the lower part of the stator so to speak. I'm sayin that when the engine is running, the oil would be evacuated from inside the rotor cavity. Since the stator aint moving, any oil on it would drip down from gravity. This all would nullify any oil level effect.

Besides, I like picking on JrWoody ( JrWooden) .

@ Mikey: Amazon, I think, even if it's rised now... let's search 55402

Reaver Reaver Reaver ....

I don't think you're drinking enough...........

Ok seriously ....
at some point in the bike's "life" ...
some amount of oil must be getting in there unless the deposits we are seeing on the stator are not oil-related ... or unless they are caused by just some oil "mist" or some such crap ... I don't know
For the sake of argument let's say that when the bike is canted over in a hard right turn that the oil level come up above the "top" of the inside lip (counterbore) of the flywheel.... what happens?

Adding resistance in the 3 wires coming from the stator - Joel was using small amount of resistance 0.1 - 0.2 ohm as I recall...

This reduces current through the stator instead of letting the R/R "short-circuit" it to ground and limit current only as result of other limitations .... heat in the stator being proportional to I^2 ... (eye-squared) seems this would help ... at least to me ... basically it turns the 400W stator into a ~320W stator based on some rough calculations I did.......

Sure wish the new design had come out while my bike was still under warranty............

PS: Indy is sending me a flywheel... guess who's gonna find out